Stripped Screw #28 on the M11A1

I just received my m11a1 (original/non-NS2 version) back from KWA after part #43 (inner piston) broke. The gun worked great for about 5 mags and then(sigh), problems began again!! When I took the magazine out a small broken piece of plastic fell out of the magwell. I figured out that the broken piece of plastic came from part #35 (external cylinder).
My problem is the same as the original problem I had with part #43, the top screw (#28) on the bolt will not budge so I end up inadvertently stripping the screw. I am very careful trying NOT to strip the screw but it is so soft and takes barely anything to strip. I used a blow dryer to heat up and hopefully loosen the screw so I can remove it so I can get to the external cylinder (#35). Any suggesions on how to get a stripped screw out?
Is there any other way that I can fix the external cyliinder (#35) without needing to remove the top screw (#28) of the bolt? I know that this may be wishful thinking but I just don't want to have to send the gun back to KWA if I can fix it myself. How did you guys get at the inner piston (#43) to change it?
Is there anything that I could be doing wrong that could have led up to the external cylinder (#35) breaking? I keep the gun well lubed and clean.
I love this gun and I don't want to give up on it just yet, but all these repairs are starting to not make economical sense.
The M11A1 NS2 is on my shortlist of guns to get because I think the NS2 system is great and it would be cool to double fist 2 m11a1's (Punisher style!) but as it stands, I'm ZERO fisting because I don't have either!!!!
Any repair advice would be appreciated. I have a lot of spare magazines invested in this gun and realize that the NS2 mags are not compatible.

I just received my m11a1 (original/non-NS2 version) back from KWA after part #43 (inner piston) broke. The gun worked great for about 5 mags and then(sigh), problems began again!! When I took the magazine out a small broken piece of plastic fell out of the magwell. I figured out that the broken piece of plastic came from part #35 (external cylinder).
My problem is the same as the original problem I had with part #43, the top screw (#28) on the bolt will not budge so I end up inadvertently stripping the screw. I am very careful trying NOT to strip the screw but it is so soft and takes barely anything to strip. I used a blow dryer to heat up and hopefully loosen the screw so I can remove it so I can get to the external cylinder (#35). Any suggesions on how to get a stripped screw out?
Is there any other way that I can fix the external cyliinder (#35) without needing to remove the top screw (#28) of the bolt? I know that this may be wishful thinking but I just don't want to have to send the gun back to KWA if I can fix it myself. How did you guys get at the inner piston (#43) to change it?
Is there anything that I could be doing wrong that could have led up to the external cylinder (#35) breaking? I keep the gun well lubed and clean.
I love this gun and I don't want to give up on it just yet, but all these repairs are starting to not make economical sense.
The M11A1 NS2 is on my shortlist of guns to get because I think the NS2 system is great and it would be cool to double fist 2 m11a1's (Punisher style!) but as it stands, I'm ZERO fisting because I don't have either!!!!
Any repair advice would be appreciated. I have a lot of spare magazines invested in this gun and realize that the NS2 mags are not compatible.

To remove the screw, go to some place like Home Depot and buy the appropriate sized screw extractor. However, I would call customer service first to see if they can help you out .